stm32f0: can: add to build

Added the CAN1 compatibility aliases as has been done for adc and dac to
make code reuse easier.  Only for the magic enums, the raw bit
definitions remain as per the ref mans

Originally suggested as https://github.com/libopencm3/libopencm3/pull/802

include/libopencm3/stm32/f0/rcc.h

@@ -437,6 +437,7 @@ enum rcc_periph_clken {
 	RCC_I2C2	= _REG_BIT(0x1C, 22),
 	RCC_USB		= _REG_BIT(0x1C, 23),
 	RCC_CAN		= _REG_BIT(0x1C, 25),
+	RCC_CAN1	= _REG_BIT(0x1C, 25), /* Compatibility alias */
 	RCC_CRS		= _REG_BIT(0x1C, 27),
 	RCC_PWR		= _REG_BIT(0x1C, 28),
 	RCC_DAC		= _REG_BIT(0x1C, 29),
@@ -475,6 +476,7 @@ enum rcc_periph_rst {
 	RST_I2C2	= _REG_BIT(0x10, 22),
 	RST_USB		= _REG_BIT(0x10, 23),
 	RST_CAN		= _REG_BIT(0x10, 25),
+	RST_CAN1	= _REG_BIT(0x10, 25), /* Compatibility alias */
 	RST_CRS		= _REG_BIT(0x10, 27),
 	RST_PWR		= _REG_BIT(0x10, 28),
 	RST_DAC		= _REG_BIT(0x10, 29),

lib/stm32/f0/Makefile

@@ -36,7 +36,7 @@ TGT_CFLAGS	+= $(STANDARD_FLAGS)
 
 ARFLAGS		= rcs
 
-OBJS		= flash.o rcc.o usart.o dma.o rtc.o comparator.o crc.o \
+OBJS		= can.o flash.o rcc.o usart.o dma.o rtc.o comparator.o crc.o \
                   dac.o iwdg.o pwr.o gpio.o timer.o adc.o desig.o
 
 OBJS            += gpio_common_all.o gpio_common_f0234.o crc_common_all.o \